Abrasive tool



Nov. 14, 1944. G. w. ALLRED 2,362,739

' ABRASIVE TOOL Filed July 10, 194.4-

Patented Nov. 14, 1944 ABRASIVE TOOL George W. Alli-ed, Mayodan, N. 0.

Application July 10, 1944, Serial No. 544,201

3 Claims. (Cl. 51-190) This invention relates to an abrasive tool of the type in which a cylindrical body is formed by winding a strip of flexible abrasive sheet material such as sand paper. The cylindrical body may be of any desired size and proportions, and

it may be in the form of a right cylinder as formed by winding a strip of uniform width or conical as formed by winding a tapered strip. It may consist of only a few turns of the abrasive sheet material wound around a large central opening and adapted to be mounted on a rotatable cylindrical drum or it may consist of many turns of the abrasive sheet material with only a relatively small central opening and adapted to be mounted on a relatively small rotatable spindle or shaft. The abrasive sheet material may be wound upon a core adapted to fit the rotatable drum or spindle, or this core may be omitted and the cylindrical body mounted directly upon the drum or spindle. Any suitable flexible abrasive sheet material such as sand paper, emery paper, emery cloth, etc.', may be used.

My invention is applicable to anyand all such abrasive tools and is concerned only with the method or means whereby! the turns of the abrasive sheet material forming the cylindrical body are held together. In accordance with my invention, a strip of non-abrasive sheet material such as paper is glued along one or both edges of 'the strip of abrasive sheet material, being glued to the non-abrasive side thereof and extending outwardly beyond the edge of theabrasive sheet material. The resulting strip of abrasive sheet material with the strip of nonlapping and secured to the edge of the abrasive strip and the other half extending beyond the edgeof the abrasive strip, has been found to be suitable in the production of drums or spindles of sand paper such as commonly is used for sanding wood surfaces.

An embodiment of the invention is shown in the accompanying drawing, it being understood from the foregoing description that this embodiabrasive sheet material glued to its edge or edges is then wound to form the cylinder and the free edge of the non-abrasive sheetmaterial extending beyond the end of the cylinder is bent over and glued down against the end of the cylinder.

The free edge of the strip of non-abrasive sheet material may be bent either outwardly or inwardly, that is toward the axis or toward the surface of the cylinder. The strip of non-abrasive material may be of anydesired thickness to produce the desired cushion effect, as will be described hereinafter. It may overlap the strip of abrasive material a suitable distance for securing the two strips together by means of adhesive and it should extend beyond the edge of the abrasive strip sufllciently to permit the free edge easily to be bent over and secured in bentover position by means of adhesive. A non-abrasive strip of medium weight wrapping paper onehalf inch wide, with about half its width overment is merely illustrative. 7

Referring to the drawing:

Fig. 1 is a side elevation'showing the end of. a cylindrical sanding wheel ,or drum;

Fig. 2 is a front elevation of the cylinder with a portion broken away to show the rotatable shaft on which the cylinder is mounted, the'core on which the abrasive sheet material is wound, and the disposition of the non-abrasive strip adiacent the axis of the cylinder;

Fig, 3 is a front elevation of a cylinder mounted on a rotatable shaft with a portion of the cylinder broken away to reveal the disposition of the non-abrasive strip adjacent the periphery of the cylinder;

Fig. 4 is a perspective view of the abrasive and non-abrasive strips secured together before winding to form the cylinder; and

In the drawing, i is the cylinder formed b winding the abrasive strip 2 and the non-abrasive strip 3 around the core or spool 4 which may be made of paper, wood, metal or other suitable material and mounted on the rotatable shaft ll.

by means of the washer 8 and the nut I. The shaft 5 is provided with the collar 8 between which and the washer 8 the cylinder is firmly held by the nut I. As will be seen from Fig. 4, the non-abrasive strips I are secured by means of adhesive along each edge of the non-abrasive surface of the abrasive strip 2. The strip 2 may down over the preceding turns.

be for instance about four inches wide and the .strip 3 about one-half inch wide. Referring to Fig. 2, it will be seen that the protruding edge of the strip 3 is bent inwardly toward the axis of the cylinder, the first turn being glued to the end of the core I and the succeeding turns being glued Fig. 3 shows the position of the overlapping glued down edges of the strips 3 adjacent the periphery of the cylinder. This figure also shows the end discs 8, 9 which may be glued to theends of the cylinder over the overlapping edges of the strips 3. It will be apparent that the strips 3 serve not only to secure the strip 2 in wound position but also to protect the ends of the cylinder and form a nonabresive surface thereon, and more particularly to avoid the application of adhesive to the abrasive surface. which is highly objectionable, and further slightly to space the turns of the abrasive strip in the cylinder and thereby to give the operating surface of the cylinder a slight flexibility which greatly improves its action. This flexibility of the cylinder permits it to yield slightly and flatten at the point of contact with the surface being sanded and gives a more gentle action of the abrasive surface without however reducing its cutting rate. The softer action of the abrasive surface on the object being sanded is compensated for by the largeramount of surface contact so that the cutting action is fully as rapid. Moreover, the softness or flexibility of the cylinder tends to avoid the production of ridges and spotty defects on the sanded surface which commonly are encountered in the use of a hard or rigid cylinder formed by tightly winding the abrasive strip without the non-abrasive strip.

It will be understood of course thatan abrasive cylinder made in accordance with my invention is used in the same way as abrasive cylinders of the prior art made by winding a flexible abrasive strip, that is. when the surface of the cylinder becomes worn or exhausted, the end of the strip is loosened and one turn of the strip torn oi! to expose a fresh abrasive surface.

1 the edge of said abrasive sheet material and eachtum of the extending portion thereof being adhesively secured to each adiacent turn thereof. 2. An abrasive wheel as defined in claim 1 in which'the turns of the extending portion of the i5 strip of non-abrasive sheet material are bent over against the end of the wheel in overlapping position.

3. An abrasive wheel as defined in claim 1 in which the turns of the extending portion of the 20 strip of non-abrasive sheet material are bent over toward the axis of the wheel in overlapping relation and adhesively secured to each other and the end of the cylinder is covered by a disc of sheet material adhesively attached to the overlapping ends of the strip of non-abrasive sheet material.

GEORGE W. ALLRED. 

